Fluid pressure apparatus with orbiting oscillator

ABSTRACT

A low speed, high-torque fluid pressure apparatus adapted for use as a reversable motor or a pump, which includes a rotor having an axis which is fixed relative to the supporting housing and containing external gear teeth which mesh with internal gear teeth on an oscillator mounted for orbital motion relative to the housing. The oscillator contains radially spaced piston cavities which receive reciprocating pistons having the outer ends thereof in limited sliding engagement with the housing. Each piston cavity has an eccentric valving assembly associated therewith for controlling the flow of fluid among the piston cavity and the housing fluid inlet and fluid outlet.

United States Patent Inventor HenryB. Chambers Santa Barbara, Calif.Appl. No. 29,398 Filed Apr. 17, 1970 Patented Oct. 19, 1971 AssigneeHydranautics Goleta, Calif.

FLUID PRESSURE APPARATUS WITH ORBITING OSCILLATOR l 1 Claims, 4 DrawingFigs.

US. Cl. 91/478, 91/481, 417/273 Int. Cl F01b 3/00, FOlb 13/04, F04b 1/04Field of Search 91/186,-

[56] References Cited UNITED STATES PATENTS 1,414,965 5/1922 Mayer91/481 2,545,315 3/1951 Sproull... 417/273 2,725,182 11/1955 Spriggs...417/273 3,339,460 9/1967 Birdwell 91/491 Primary Examiner-Carlton R.Croyle Assistant Examiner.lohn J. Vrablik Attorney- Nilsson, Robbins,Wills & Berliner ABSTRACT: A low speed, high-torque fluid pressureapparatus adapted for use as a reversable motor or a pump, whichincludes a rotor having an axis which is fixed relative to thesupporting housing and containing external gear teeth 1 which mesh withinternal gear teeth on an oscillator mounted for orbital motion relativeto the housing. The oscillator contains radially spaced piston cavitieswhich receive reciprocating pistons having the outer ends thereof inlimited sliding engagement with the housing. Each piston cavity has aneccentric valving assembly associated therewith for controlling the flowof fluid among the piston cavity and the housing fluid inlet and fluidoutlet.

FLUID PRESSURE APPARATUS WI'I'I'I ORBITING OSCILLATOR BACKGROUND OF THEINVENTION The present invention relates generally to fluid pressureapparatus, and more particularly to a novel low speed, hightorque radialpiston fluid pressure apparatus with an orbiting oscillator, which isadapted for use as a reversible motor or a reversible pump.

In the same general field of fluid pressure apparatus, there are variousdevices which can operate as a low speed, hightorque motor or pump, andwhich include any internallytoothed cylindrical member which meshes withand has rotational movement relative to an extemally-toothed membercontaining an unlike number of complimentary teeth. However, most ofsuch devices are large and cumbersome, have problems with fluid sealsand valving arrangements, and usually require a wobble shaft between thedriven member and the power take off, with its attendant wear bearingproblems.

SUMMARY OF THE INVENTION With the aforementioned limitations anddeficiencies of presently known apparatus in mind, it is an object ofthe present invention to provide a novel, low speed, high-torque fluidpressure apparatus which can be used as a reversible fluid motor or areversible fluid pump, and which is compact in size and of relativelylight weight as compared with its output.

A further object is to provide such a fluid pressure apparatus which isgenerally of disclike or flat cylindrical configuration with athrough-shaft construction, whereby a plurality of such units can beconveniently stacked side-by-side and connected in tandem to increasethe power output in proportion to the number of units so interconnected.

Yet another object is to provide sucha fluid pressure apparatus havingan orbiting component which directly drives or is driven by a rotor orshaft, the axis of which remains stationary relative to the housing.More particularly, it is an object to provide such a fluid pressureapparatus which can be used as a motor or a pump and in which the rotoror shaft is supported in spaced-apart fixed bearings. Specifically, itis an object to provide such a low speed, high-torque fluid apparatuswith an orbiting component, which when used as a motor contains a rotoror driven shaft supported in spaced-apart fixed hearings to facilitatesupporting overhung shaft loads such as occur with winches, wheel drivesand chain or belt drives.

An additional object, which is related to the immediately precedingobject, is to provide such a low speed, high-torque fluid motorcontaining an orbiting component, in which the driven shaft has an axiswhich is fixed relative to the supporting housing, whereby the drivenmember can take the form of a large diameter, hollow rotor for use as adrill rig rotary table, or to receive a conventional drill bar of anaugar.

A further object is to provide such a novel low speed, hightorque fluidpressure apparatus with an orbiting component, in which the valvingassembly is actuated by the orbiting component. More particularly, it isan object to provide a valving assembly for such an apparatus, whichcontains relatively few parts and which permits the use of relativelyhigh fluid pressures, i.e., about 5,000 lb. per sq. inch.

Yet another object of the present invention is to provide a novel fluidmotor which has generally universal application for installations whichrequire a low speed, high-torque prime mover, as for example withaugars, drill rigs, winches, tunneling machinery, and off-roadgraders... to name a few.

I have discovered that the aforementioned objects and advantages arefulfilled by a fluid pressure apparatus constructed in accordance withthe teachings of the present invention, which includes a housing havinga fluid inlet and a fluid outlet; a shaft or rotor with external teethmounted in the housing for rotation about a fixed axis; an annularoscillator member with internal teeth mounted for orbiting movement(without rotation) about the shaft with the teeth in engagement; aplurality of circumferentially spaced fluid pistons between the housingand the oscillator member for radial movement relative to the lattermember; and fluid flow control means associated with the pistons andresponsive to the orbiting of the oscillator member.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a vertical sectional view of a fluid pressure apparatus withorbiting oscillator embodying the teachings of the present invention,the sectional view being taken on a plane transverse to the axis of therotor shaft;

FIG. 2 is a longitudinal vertical sectional view taken on the line 2-2in FIG. 1 with some of the parts being shown in elevation and with thebearings being shown schematically;

FIGS. 3a-3e are enlarged fragmentary transverse sectional views of oneof the eccentric assemblies shown in FIG. 1, illustrating in astep-by-step sequence the manner in which the eccentric member rotatesabout its associated journal shaft as the oscillator member orbitsrelative to the housing; and

FIG. 4 is a transverse sectional view taken on the line 4-4 in FIG. 32,and rotated DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to thedrawings more particularly by reference numerals, the number 10indicates generally a fluid pressure apparatus with orbiting oscillatorconstructed in accordance with the teachings in the present invention,which for convenience of description, will he described as a fluid motorinsofar as concerns the direction of the flow of fluid therethrough, andthe description of the driving and the driven members.

The fluid pressure apparatus 10 includes a housing 12 (FIG. 2) which isgenerally cuplike in shape with an endwall portion 14 having an inletface 15 and containing a rotor aperture 16 and a sidewall or peripheralwall portion I8. The interior of the housing is provided with a circularoscillator cavity 20 and a counterbored bearing cavity 21, both of whichare concentric with the rotor aperture 16.

A plurality'of circularly spaced fluid inlet passageways 22 extend fromthe inlet face 15 through the end wall 14, and intersect and are influid communication with an annular fluid distribution passageway 23also formed in said end wall 14. All except one of the inlet passagewaysare closed with conventional pipe plugs (not shown).

The end of the housing opposite from the rotor aperture 16 is fittedwith a removable end plate 24 having an outlet face 25 with a rotoraperture 26 adjacent the center thereof and containing a bearing cavity27 therein. The end plate 24 is mounted on the housing with alternatelypositioned, spacedapart machine screws 28 and tapered dowel pins 29,said pins facilitating the mounting of the end plate on the housingprior to the use of the machine screws for holding purposes.

A plurality of circularly spaced fluid outlet passageways 30 (FIG. 2)extend from the outlet face 25 through the end plate 24 in axialalignment with the inlet passageways 22, said outlet passagewaysintersecting and being in fluid communication with an annular fluidcollecting passageway 31 formed in the end plate 24. As with the inletpassageways, all but one of the fluid outlet passageways are closed withconventional pipe plugs (not shown).

Bearing cones 32 and 33 are positioned in the bearing cavities 21 and27, respectively, to rotatably support a tubular rotor member 34 havingends which extend through the rotor apertures 16 and 26. The outersurface of the rotor member 34 contains a set of external gear teeth 35adjacent the center portion thereof, and the interior of the tubularrotor member contains a longitudinally extending key slot 36 (FIG. 1).

As shown in FIG. 2, a cylindrical shaft 38 with a corresponding key slot40 (FIG. 1) extends into the tubular rotor member from the housing sideof the assembly, and the rotor and shaft are removably held together bya key member 42 of conventional construction. It is to be noted that theshaft 38 could extend completely through the rotor members 34 or that asecond shaft (not shown) could be inserted into the rotor member fromthe end plate side of the assembly.

Mounted within the oscillator cavity 20 (FIG. 1) for orbital movement(without rotation) relative to the housing 12, is a generally annularplatelike oscillator member 44 with (in this particular embodiment) fiveouter peripheral faces 46 and internal gear teeth 48 which mesh with theteeth 35 on the rotor member 34 in a manner which will be described morefully hereinafter. As indicated in FIG. 1, the gear teeth 48 are greaterin number than the number of gear teeth 35. Although gear teeth areshown and described, it will be understood that other types of meshingelements or lobes can be used.

Formed centrally in the outer peripheral faces 46 of the oscillatormember 44 are radially extending, circumferentially spaced cylindricalpiston cavities 50A-50E which slidably receive cylindrical pistons52A-52E, respectively, each piston having an inner face or end 53. Theouter end of each piston is recessed to provide an outer end cavity 54surrounded by an annular wall having a sealing face 56, each cavitybeing in fluid communication with its main piston cavity by means of oneor more longitudinally extending channels 58. As appears in FIG. I, theinner face 53 of each piston has a greater surface area than the outerface of the end cavity, whereby the fluid pressure is greater on theinner face than on the outer face, for a purpose to appear.

Positioned within the oscillator cavity 20 and mounted on the inner faceof the sidewall 18 are five platelike piston seat blocks 60 (FIG. 1),each of which has a flat inner face 62 to slidably receive the annularbearing face 56 of its associated piston 52. The bearing face 56 and theblock face 62 are ground flat and lapped to provide a fluid sealtherebetween.

Formed in the oscillator member 44 intermediate the piston cavities, aretransversely extending, generally cylindrical eccentric or fluid flowcontrol cavities 64 (FIG. 2), each of which is provided with an innershoulder 66 and an outer shoulder 68 for the purpose of providing fluidseals, as will appear.

Received in the eccentric cavities are cylindrical eccentric members70A-70E, the outer surfaces of which are spaced from the inner walls ofthe eccentric cavities 64 to provide annular eccentric fluid passages72A-72E between spaced-apart bearings 74 and 76 which provide for therotation of the eccentric members in the eccentric cavities.

One sealing ring 78 is positioned against the shoulder 66 in eacheccentric cavity adjacent the bearing 76, and a second sealing ring 80is positioned adjacent the bearing 74, the ring 80 being held inposition by a threaded retainer ring 82.

Piston inlet and exhaust passages 84A-84E (FIG. 1) extend between eachannular eccentric passageway 72A-72E and its associated piston cavity50A-50E, respectively, to provide for reverse fluid flow therebetween.

The eccentric members 70A-70E contain offcenter transversely extendingjournal shaft cavities 86A-86E which are in axial alignment with thefluid inlet passageways 22 in the housing 12 and with the outletpassageways 30 in the end plate 24, (FIG. 2).

Elongated, cylindrical journal shafts 88A-88E are rotatably received inthe journal shaft cavities 86A-86E (FIG. 2) and project into the inletpassages 22 and the outlet passages 30, each journal shaft beingmaintained in a selected, fixed position relative to the housing 12 (andthe end plate 24) by means of a set screw 90.

Each journal shaft 88 (FIG. 4) contains diametrically opposed oval,dish-shaped ports 92(A-E) and 94(A-E) adjacent the center thereof with apartition 95 (A-E) therebetween, each port 92(A-E) being incommunication with an axially extending inlet passage 96(A-E) in one endof the journal shaft, and each port 94(A-E) being in communication witha like outlet passage 98(A-E) in the other end of said shaft. Thetolerance between each journal shaft 88 and its associated eccentricmember 70 is such that there is a fluid seal between the two members,even though there is also relative rotational movement therebetween.

As shown in FIG. 1, each of the eccentric members 70(A-E) is providedwith a radial passage 100(A-E) which extends from the eccentric annularpassage 72(A-E) surrounding the eccentric, to adjacent the oval inletport 92(A-E) or outlet port 94(A-E).

As will be described more fully hereinafter, depending upon the rotatedposition of each eccentric relative to its associated journal shaft, theeccentric radial passageway 100 can be blocked by the partition 95, orthe eccentric radial passage 100 can be in fluid communication (to agreat or a lesser degree) with either the inlet port 92 and the inletpassage 96 or with the outlet port 94 and the outlet passage 98.

Referring to FIG. 2 and assuming that the apparatus is to function as afluid motor, high-pressure fluid will enter the inlet passageway 22 andfill the high-pressure fluid distributing passageway 23, from where itwill flow into the journal shaft inlet passageways 96A-96E and toadjacent the inlet ports 92A-93E. If an inlet port 92(A-E) is incommunication with an eccentric radial passageway 100 (FIG. 1), fluidunder pressure will flow through the port and the radial passageway tothe associated eccentric annular passage 72(AE), through the associatedpiston inlet and exhaust passageway 84(A-E), and into the associatedpiston cavity 50(A-E).

If, on the other hand, the oval outlet port 94(A-E) in a particularjournal shaft 88(A-E) is in communication with the eccentric radialpassage l00(A-E), the flow will be away from the piston cavity. Thus,the exhaust or outlet flow will be from the piston cavity 50(A-E),through the inlet and exhaust passage 84(A-E), into the eccentricannular passage 72( A-E) through the eccentric radial passage (100(A-E),into the oval outlet port 94(A-E), through the journal shaft outletpassage (A45), and into the annular low-pressure fluid collectingpassageway 31, from where it can be exhausted through the fluid outletpassageway 30.

As previously described, each journal shaft 88 is maintained in apredetennined rotated position relative to the housing 12 and the endplate 24 by the setscrew 90.

Referring to FIG. 1, and assuming that the apparatus is to be utilizedas a fluid motor with the shaft 38 rotating in the clockwise direction,the oscillator member 44 will orbit in the counterclockwise directionbecause of the sequential action of the pistons 52A-52E. Thus, it willbe noted that piston cavity 50A is almost filled with fluid underpressure with the inlet port 92A being in communication with theeccentric radial passageway 100A, that piston cavity 50B is starting tofill, and that piston cavity 50C is at an inoperative or at restposition because its eccentric radial passageway is blocked and is notin communication with either the inlet port 92C or the outlet 94C.However, both piston cavities 50D and 50E are in communication withtheir respective outlet ports 94D and 94E, whereby fluid is flowing fromthese piston cavities.

Accordingly, as the piston cavities fill under pressure in thecounterclockwise direction (or more accurately, as fluid under pressureis forced into the piston cavity so as to force the piston out of thecavity and thereby move the oscillator member 44 away from the pistonseat block), the oscillator member 44 will orbit in the samecounterclockwise direction, and, in turn, will cause each eccentricmember 70 to rotate about its journal shaft 88 in the counterclockwisedirection to cause the inlet and outlet ports to be brought intocommunication with the eccentric radial passageway in sequence tocontinue the orbiting of the oscillator member so long as there is fluidpressure in the fluid distributing passageway 23.

Torque produced in the rotor member 34 by forces acting between the gearteeth 35 and the gear teeth 48 will ultimately be transmitted to thehousing 12. Thus, assuming high pressure in the cavity 23, rotor member34 (FIG. 1) will rotate in the clockwise direction. The force applied tothe teeth 48 by the teeth 35 results in a counterclockwise torquecomponent applied to the oscillator member 44, which, in turn, is transmitted through the bearings 74 and 76 (FIG. 2) and through the eccentricmembers 70(A-E) to the journal shafts 88(A-E) which are fixed relativeto the housing 12. This counterclockwise load or torque component isresisted by high pressure fluid in each inlet port 92 (A-E), with eachof said ports facing the clockwise direction against the aforementionedload. This is a form of hydraulic balancing, similar to the fluidbalancing of pistons 52(A-E) as will be described hereinafter. Pressurebalancing by the journal shaft inlet and outlet ports 92(A-E) and94(A-E) is effective for either direction of rotation by the rotormember 34 and reduces the unit journal shaft loading to a minimum.

FIG. 3 illustrates the manner in which each eccentric member and itsradial passageway 100 rotates about the journal shaft and its outlet andinlet ports. Thus, FIG. 3a is actually an enlarged fragmentary view ofeccentric member 70A which appears adjacent the top in FIG. 1, and inwhich the eccentric radial passageway 100A is moving in acounterclockwise direction past the inlet port 92A, and toward thepartition 95A. In the next position shown, FIG. 3b, the eccentric member70A has been rotated (because of the orbiting of the oscillator member44) to a position in which the eccentric radial passageway 100A is inalignment with the partition 95A which occurs when each piston 52 is atits fully extended position, and there is no fluid flow relative to thepiston cavity 50A. In FIG. 3c, the eccentric radial passageway 100A isin communication with the outlet port 94A, and therefore piston cavity50A is exhausting to the low pressure fluid collecting passageway 31, inthe manner previously described. FIG. 3d shows the exhausting or ventingof the piston cavity 50A as continuing, the FIG. 3e shows the partition95A in alignment with the eccentric radial passageway 100A... whichrelationship occurs when each piston 52 is at its fully exhaustedposition (as illustrated by the position of piston 52C in FIG. 1).Lastly, FIG. 3f illustrates the position of the eccentric radialpassageway 100A when it again is in communication with the inlet port92A. Further rotation of the eccentric member about its journal shaft,brings the eccentric radial passageway 100A to the position firstdescribed with reference to FIG. 3a, thereby completing the cycle.

Thus, it will be apparent that there has been provided a very simple buteffective working arrangement utilizing the orbiting of the oscillatormember to rotate the eccentric members about the journal shafts, wherebyeach eccentric radial passageway 100 is alternately in communicationwith its inlet port or its outlet port, with the transition from onesuch port to the other port being interrupted by the partition 95blocking the radial passageway.

To reverse the direction of rotation of the shaft 38, it is onlynecessary to reverse the flow of fluid through the apparatus, Lee. toconnect the inlet or high-pressure line to passageway 30, and to connectthe outlet or low-pressure line to passageway 22. The oscillator member44 will orbit and the eccentric members will rotate in the clockwisedirection. This will cause the shaft 38 to rotate in thecounterclockwise direction.

As previously described, the annular sealing face 56 of each piston 52is in sliding sealing engagement with the face 62 of the associatedpiston seat block 60, and will move back and forth across said face asthe oscillator member 44 orbits about the shaft 38. Inasmuch as thechannel 58 interconnects the piston cavity 50 with the cavity 54adjacent the outer end of the piston, the fluid pressures in thecavities at the opposite ends of each piston are substantially equal.However, because the surface area at the inner face 53 is greater thanthe surface area at the outer end, the force on the inner face isgreater than the force on the outer end of the piston, whereby theannular bearing faces 56 are maintained in fluid sealing relationshipwith the block faces 62. However, because the pressures are nearlybalanced, there is a minimum amount of friction between the block face62 and the annular bearing face 56 of the associated piston.

To use the apparatus as a reversible fluid pump, the shaft 38 would berotated in either direction, which in turn will cause the oscillatormember 44 to orbit about the shaft and move the pistons within thepiston cavities so as to create a vacuum in the piston cavities whichare enlarging, and thereafter force the fluid from such cavitieswhen-the piston moves inwardly relative to the oscillator member. Oneminor change is necessary when the apparatus is to be used as a pump,and that is that it is necessary to use coiled springs (not shown) inthe piston cavities in order to maintain the sealing faces 56 at theouter ends of the pistons in engagement with the faces 62 of the seatblocks.

The oscillator member 44, the pistons 52(A-E) and the eccentric members70(A-E) fonn an orbiting group of elements which function to provideautomatic fluid valving, a load path between the rotor member 34 and thehousing 12, and proper positioning of the major components so as tomaintain the gear teeth in proper meshing relationship.

As mentioned hereinabove, the particular embodiment which has been shownand described is the preferred construction. An alternative constructionwould eliminate the piston seat blocks 60 and replace the cylindricalpistons 52(A-E) with spherical pistons (not shown) which would havelimited rolling travel on the inner surface of the wall 18 (FIG. 1).

Thus, it is apparent that there has been provided a low speed,high-torque fluid pressure apparatus which can be used as either areversible motor or a reversible pump and which fulfills all of theobjects and advantages sought therefor. The axis of the rotor is fixedrelative to the housing so as to obviate the use of a wobble connector,the apparatus is relatively small in size for its power output and of aconfiguration to facilitate connecting multiple units in tandem, thereare relatively few parts, and the relationship of the parts is such asto permit the use of relatively high-fluid pressures without leakage.

What is claimed is:

l. A fluid motor, comprising:

a housing having a fluid inlet and a fluid outlet;

a shaft with external teeth mounted in the housing for rotation about afixed axis;

an annular oscillator member with an outer peripheral portion andinternal teeth mounted in the housing about said shaft;

the number of external teeth on the shaft being less that the number ofinternal teeth on the oscillator member, and the teeth on the oscillatormember being adapted to mesh with the teeth on the shaft; and

fluid pressure responsive means between the oscillator member and thehousing in selective communication with the fluid inlet and fluid outletthrough fluid flow control means for causing the oscillator member toorbit without rotation about the shaft with the teeth on the oscillatormember in driving engagement with the teeth on the shaft.

2. The fluid motor described in claim 1 in which the fluid pressuremeans comprises a plurality of pistons slidably mounted in pistoncavities formed in the outer peripheral portion of the oscillatormember.

3. The fluid motor described in claim 1 in which the fluid pressuremeans comprises a plurality of pistons circumferentially spaced aboutthe oscillator member and slidably mounted in piston cavities formedradially in the outer peripheral portion of said member, the outer endof each piston being in sliding engagement with a piston seat block infixed position relative to the housing.

4. The fluid motor described in claim 3 in which:

each piston has an inner end face;

the outer end of each piston contains an annular ridge defining an endcavity with an outer end face, said outer end face being of less areathan the inner end face of the 5. A fluid motor,- comprising:

a housing having a fluid inlet and a fluid outlet;

a shaft with external teeth mounted in the housing for rotation about afixed axis;

an annular oscillator member with an outer peripheral portion andinternal teeth mounted in the housing about said shaft;

' the number of external teeth on the shaft being less that the numberof internal teeth on the oscillator member, and the teeth on theoscillator member being adapted to mesh with the teeth on the shaft;

a plurality of fluid pressure responsive units between the oscillatormember and the housing; and

fluid flow control means associated with the oscillator member andresponsive to the movement thereof for controlling the flow of fluidamong said pressure responsive units and the fluid inlet and the fluidoutlet to cause said oscillator member to orbit without rotation aboutthe shaft with the teeth on the oscillator member in driving engagementwith the teeth on the shaft.

6. The fluid motor described in claim in which the fluid flow controlmeans includes a plurality of eccentric members rotatably mounted on theoscillator member, each eccentric member having inlet and outlet portsassociated therewith which are alternately opened and closed as theeccentric member rotates relative to the oscillator member.

7. The fluid motor described in claim 5 in which the fluid flow controlmeans includes:

a plurality of spaced apart, transversely extending eccentric cavitiesin the outer peripheral portion of the oscillator member;

a journal shaft with outlet and inlet ports extending through eacheccentric cavity, each journal shaft being in a fixed position relativeto the housing; and

an eccentric member in each eccentric cavity mounted for rotation withinthe cavity and about the journal shaft, each eccentric member containinga radially extending fluid passageway which is adapted to alternatelycommunicate with said outlet and inlet ports as the eccentric memberrotates around the journal shaft,

8. The fluid motor described in claim 7 in which each journal shaft isof cylindrical configuration and contains diametrically opposed inletand outlet ports at the surface thereof; and means are provided foradjusting the angular position of each journal shaft relative to thehousing.

9. The fluid motor described in claim 5 in which the fluid flow controlmeans includes:

a plurality of circumferentially spaced, transversely extendingeccentric cavities in the outer peripheral portion of the oscillatormember;

a cylindrical member mounted in each eccentric cavity for rotation aboutthe axis of the eccentric member;

a journal shaft cavity extending through each eccentric member parallelwith and offset from the axis thereof;

a radially extending passage in each eccentric member in fluidcommunication with its journal shaft cavity; and

a cylindrical journal shaft which is fixed relative to the housingextending through each journal shaft cavity, each journal shaftcontaining diametrically opposed inlet and outlet ports for selectivecommunication with the radial passage as theeccentric member rotates inthe eccentric cavity relative to the journal shaft.

10. Fluid pressure apparatus, comprising:

a housing having a fluid inlet and a fluid outlet;

a shaft with external gear teeth mounted in the housing for rotationabout a fixed axis;

an annular oscillator member with an outer peripheral portion andinternal teeth mounted in the housing about said shaft for orbitalmovement without rotation relative to the shaft and the housing;

the number of internal teeth on the oscillator member being greater thanthe number of teeth of the shaft, and the teeth on the oscillator memberbeing adapted to mesh with the teeth on the shaft; a plurality ofclrcumferentially spaced, radially extending piston cavities in theouter peripheral portion of the oscillator member;

a piston with inner and outer ends slidably mounted in each pistoncavity, the outer end of each piston being in sliding engagement with apiston seat block which is fixed relative to the housing;

a plurality of fluid flow control cavities in the outer peripheralportion of the oscillator member intermediate the piston cavities, therebeing one control cavity for each associated piston cavity;

an inlet-exhaust fluid passageway between each fluid flow control cavityand its associated piston cavity;

a flow control assembly in each flow control cavity in communicationwith the housing outlet for controlling the flow of fluid among theinlet-exhaust passageway and said housing inlet and housing outletduring the orbital movement of the oscillator member, whereby eachpiston cavity will receive and discharge fluid in sequence.

11. Fluid pressure apparatus as described in claim 10 wherein each flowcontrol cavity is of cylindrical shape and each flow control assemblyincludes:

a cylindrical journal shaft extending through the flow control cavityoffset from the axis of said cavity and containing spaced-apart inletand outlet ports in fluid communication with the housing inlet and thehousing outlet, respectively; and

a cylindrical eccentric member mounted in the flow control cavity forrotation about the journal shaft as the oscillator member orbits, andincluding a radial passageway in communication with the flow controlcavity and in selective communication with said inlet and outlet portsof the journal shaft during rotation.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 361351ODated October 19, 1971 Inventor-(s) Henry h mbers It is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Column line 21, "92A-93E" should read 92A-92E line 35, "housing outletfor controlling" should Column 8, read housing inlet and housing outletfor controlling Signed and sealed this 29th day of August 1972.

(SEAL) Attest:

ROBERT GOTTSCHALK EDWARD M.FLETCHER,JR.

Commissioner of Patents Attesting Officer USCOMM-DC 6O376-P69 u.s.GOVERNMENT PRINTING OFFICE may o -3ss-33A ORM F'O-105O (10-69)

1. A fluid motor, comprising: a housing having a fluid inlet and a fluidoutlet; a shaft with external teeth mounted in the housing for rotationabout a fixed axis; an annular oscillator member with an outerperipheral portion and internal teeth mounted in the housing about saidshaft; the number of external teeth on the shaft being less that thenumber of internal teeth on the oscillator member, and the teeth on theoscillator member being adapted to mesh with the teeth on the shaft; andfluid pressure responsive means between the oscillator member and thehousing in selective communication with the fluid inlet and fluid outletthrough fluid flow control means for causing the oscillator member toorbit without rotation about the shaft with the teeth on the oscillatormember in driving engagement with the teeth on the shaft.
 2. The fluidmotor described in claim 1 in which the fluid pressure means comprises aplurality of pistons slidably mounted in piston cavities formed in theouter peripheral portion of the oscillator member.
 3. The fluid motordescribed in claim 1 in which the fluid pressure means comprises aplurality of pistons circumferentially spaced about the oscillatormember and slidably mounted in piston cavities formed radially in theouter peripheral portion of said member, the outer end of each pistonbeing in sliding engagement with a piston seat block in fixed positionrelative to the housing.
 4. The fluid motor described in claim 3 inwhich: each piston has an inner end face; the outer end of each pistoncontains an annular ridge defining an end cavity with an outer end face,said outer end face being of less area than the inner end face of thepiston; and fluid communication means are provided between the pistoncavity and the end cavity.
 5. A fluid motor, comprising: a housinghaving a fluid inlet and a fluid outlet; a shaft with external teethmounted in the housing for rotation about a fixed axis; an annularoscillator member with an outer peripheral portion and internal teethmounted in the housing about said shaft; the number of external teeth onthe shaft being less that the number of internal teeth on the oscillatormember, and the teeth on the oscillator member being adapted to meshwith the teeth on the shaft; a plurality of fluid pressure responsiveunits between the oscillator member and the housing; and fluid flowcontrol means associated with the oscillator member and responsive tothe movement thereof for controlling the flow of fluid among saidpressure responsive units and the fluid inlet and the fluid outlet tocause said oscillator member to orbit without rotation about the shaftwith the teeth on the oscillator member in driving engagement with theteeth on the shaft.
 6. The fluid motor described in claim 5 in which thefluid flow control means includes a plurality of eccentric membersrotatably mounted on the oscillator member, each eccentric member havinginlet and outlet ports associated therewith which are alternately openedand closed as the eccentric member rotates relative to the oscillatormember.
 7. The fluid motor described in claim 5 in which the fluid flowcontrol means includes: a plurality of spaced apart, transverselyextending eccentric cavities in the outer peripheral portion of theoscillator member; a journal shaft with outlet and inlet ports extendingthrough each eccentric cavity, each journal shaft being in a fixedposition relative to the housing; and an eccentric member in eacheccentric cavity mounted for rotation within the cavity and about thejournal shaft, each eccentric member containing a radially extendingfluid passageway which Is adapted to alternately communicate with saidoutlet and inlet ports as the eccentric member rotates around thejournal shaft.
 8. The fluid motor described in claim 7 in which eachjournal shaft is of cylindrical configuration and contains diametricallyopposed inlet and outlet ports at the surface thereof; and means areprovided for adjusting the angular position of each journal shaftrelative to the housing.
 9. The fluid motor described in claim 5 inwhich the fluid flow control means includes: a plurality ofcircumferentially spaced, transversely extending eccentric cavities inthe outer peripheral portion of the oscillator member; a cylindricalmember mounted in each eccentric cavity for rotation about the axis ofthe eccentric member; a journal shaft cavity extending through eacheccentric member parallel with and offset from the axis thereof; aradially extending passage in each eccentric member in fluidcommunication with its journal shaft cavity; and a cylindrical journalshaft which is fixed relative to the housing extending through eachjournal shaft cavity, each journal shaft containing diametricallyopposed inlet and outlet ports for selective communication with theradial passage as the eccentric member rotates in the eccentric cavityrelative to the journal shaft.
 10. Fluid pressure apparatus, comprising:a housing having a fluid inlet and a fluid outlet; a shaft with externalgear teeth mounted in the housing for rotation about a fixed axis; anannular oscillator member with an outer peripheral portion and internalteeth mounted in the housing about said shaft for orbital movementwithout rotation relative to the shaft and the housing; the number ofinternal teeth on the oscillator member being greater than the number ofteeth of the shaft, and the teeth on the oscillator member being adaptedto mesh with the teeth on the shaft; a plurality of circumferentiallyspaced, radially extending piston cavities in the outer peripheralportion of the oscillator member; a piston with inner and outer endsslidably mounted in each piston cavity, the outer end of each pistonbeing in sliding engagement with a piston seat block which is fixedrelative to the housing; a plurality of fluid flow control cavities inthe outer peripheral portion of the oscillator member intermediate thepiston cavities, there being one control cavity for each associatedpiston cavity; an inlet-exhaust fluid passageway between each fluid flowcontrol cavity and its associated piston cavity; a flow control assemblyin each flow control cavity in communication with the housing outlet forcontrolling the flow of fluid among the inlet-exhaust passageway andsaid housing inlet and housing outlet during the orbital movement of theoscillator member, whereby each piston cavity will receive and dischargefluid in sequence.
 11. Fluid pressure apparatus as described in claim 10wherein each flow control cavity is of cylindrical shape and each flowcontrol assembly includes: a cylindrical journal shaft extending throughthe flow control cavity offset from the axis of said cavity andcontaining spaced-apart inlet and outlet ports in fluid communicationwith the housing inlet and the housing outlet, respectively; and acylindrical eccentric member mounted in the flow control cavity forrotation about the journal shaft as the oscillator member orbits, andincluding a radial passageway in communication with the flow controlcavity and in selective communication with said inlet and outlet portsof the journal shaft during rotation.